© 2007 m. tallman. look right next door. 3. find your number. 7 round to the nearest one (units). 4...

© 2007 M. Tallman

© 2007 M. Tallman

Look right next door.

3.

Find your number.

7

Round to the nearest one (units).

4

Step 1: Circle the digit in the place that you must round to.

Step 2: Draw an arrow to the place on the right.

© 2007 M. Tallman

0073

4 or less, just ignore.

.4

Step 1: Circle the digit in the place that you must round to.

Step 2: Draw an arrow to the place on the right.

Step 3: If the number is four or less, then the circled number stays the same.

Step 4: All numbers to the right of the circled number become zeros, or disappear.

3 is less

than 4

Just Ignore!

Round to the nearest tenth.

© 2007 M. Tallman

4.37 rounded to the nearest one (unit)

is…44 54.37

4.37 is closer to 4 on the number line.

© 2007 M. Tallman

Look right next door.

8.

Step 1: Circle the digit in the place that you must round to.

Step 2: Draw an arrow to the place on the right.

Find your number.

Round to the nearest one (units).

2

© 2007 M. Tallman

803

4 or less, just ignore.5 or more, add 1 more.

Step 1: Circle the digit in the place that you must round to.

Step 2: Draw an arrow to the place on the right.

Step 3: If the number is four or less, then the circled number stays the same.

Step 4: If the number is 5 or greater, then add 1 to the circled number.

Step 5: All numbers to the right of the circled decimal number become zeros, or disappear.

8 is not less

than 42 + 1 =

3

.2

Round to the nearest one (units).

© 2007 M. Tallman

2.8 rounded to the nearest one (unit)

is…32 32.8

2.8 is closer to 3 on the number line.

© 2007 M. Tallman

17.4 + 4.8

17 5+ = 22Step 1: Rounding is always first. Decide which place to round to.

Step 2: Round each addend to the nearest whole number.

The actual answer is 22.2,

so our estimation is

pretty accurate.

The actual answer is 22.2,

so our estimation is

pretty accurate.

Step 3: Now you can add 17 and 5 mentally.

© 2007 M. Tallman

9.7 + 2.8

10 3+ = 13Step 1: Rounding is always first. Decide which place to round to.

Step 2: Round each addend to the nearest whole number.

The actual answer is 12.5,

so our estimation is

pretty accurate.

The actual answer is 12.5,

so our estimation is

pretty accurate.

Step 3: Now you can add 10 and 3 mentally.

© 2007 M. Tallman

42.8 + 6.3

43 6+ = 49Step 1: Rounding is always first. Decide which place to round to.

Step 2: Round each addend to the nearest whole number.

The actual answer is 49.1,

so our estimation is

pretty accurate.

The actual answer is 49.1,

so our estimation is

pretty accurate.

Step 3: Now you can add 43 and 6 mentally.

© 2007 M. Tallman

1. 19.76 + 9.55

$24.00

2315 + 8 =

157 + 8 =

30

4. $23.87 + $6.70

3. 14.7 + 8.3

Estimate Each Sum

2. 7.45 + 8.56

20 + 10 =

$31.00+$7.00 =

© 2007 M. Tallman

$103.00

5. 13.56 + 4.4

$5.00

$112.00$9.00+ =

171 + 16 =

18

8. $4.77 + $28.70

7. $9.33 + $102.5

Estimate Each Sum

6. 0.78 + 15.89

14 + 4 =

$34.00+$29.00 =

© 2007 M. Tallman

$2.00

9. $3.26 + $14.67

0

$32.00$30.00 + =

396 + 33 =

$18.00

12. 0.23 + 12.67

11. $29.53 + $2.45

Estimate Each Sum

10. 6.42 + 33.31

$3.00+$15.00 =

13+ 13 =